I, and a good portion of this board, will tell you to stay away from the 767-400 "coffin" seats - they are widely (and, IMO, correctly) identified as the worst D1 seats that DL puts in the air. The A330 on the other hand are one of the best - given Alitalia's perpetually precarious position around going out of business, I would highly recommend the DL-metal A330 as being your best option.